This invention relates generally to nuclear reactors, and more particularly, to reinforcement ring plates for openings in a reinforced concrete containment vessel that encloses a nuclear reactor.
The containment vessel is a necessary component in a nuclear power plant. It prevents the release of radioactive material to the environment in the event of a component failure inside the containment vessel. Typically, containment vessels are constructed with reinforced concrete and take the form of a cylindrical shell supported on a reinforced concrete foundation and closed at the top by a reinforced concrete slab. Penetrations through the reinforced concrete containment vessel (RCCV) shell are installed to allow for the passage of steam lines, feedwater lines, emergency cooling lines, instrumentation and control lines, and/or electrical power lines. In addition, openings in the cylindrical shell are often times needed for equipment hatches and personnel access.
There are many various types of loads on an RCCV shell at any given point in time, such as structural loads, seismic loads, hydrodynamic loads, internal pressure loads due to loss of coolant accidents, and reaction loads due to the support of pipes. Consequently, RCCV shells are typically equipped with large size reinforcing steel bars, or rebars, in order to handle the above described loads. When these reinforcing bars encounter a large opening in the RCCV either for a penetration or an access hatch, the reinforcing bars have to be terminated. This results in an interruption of the reinforcing bars, which can affect the transfer of loads and reduce the ability to maintain equilibrium conditions.
As a result, additional reinforcing bars or reinforcing steel frames are often installed around the opening in order to facilitate load transfer. However, this results in congestion problems that complicate the structure and complicate RCCV shell construction. An alternative solution is to locally increase the shell wall thickness around the opening. However increased wall thickness takes up space and sometimes interferes with the arrangement of critical reactor components and structures in adjacent areas. Consequently, it is desirable to provide a load transfer mechanism for reinforcing bars around an opening in an RCCV shell.
In an exemplary embodiment, a reinforced concrete containment vessel (RCCV) for a nuclear reactor in a nuclear power plant includes a cylindrical shell having a side wall with at least one opening therethrough. The RCCV also include a plurality of reinforcing bars, at least one of which is interrupted at the shell wall opening. A reinforcing plate having an opening is located in the shell wall so that the reinforcing plate opening is aligned with the shell wall opening and the interrupted reinforcing bars are connected to the reinforcing plate.
A penetration sleeve is positioned in the reinforcing plate opening. The penetration sleeve has an outer diameter that is smaller than the corresponding reinforcing plate opening, and is secured to the reinforcing plate. Reinforcing bars include vertical reinforcing bars and horizontal hoop reinforcing bars. Reinforcing bar terminators connect the reinforcing bars to the reinforcing plate. The reinforcing bars and the reinforcing plate are fabricated from structural steel.